Computed tomography (CT) has been widely used in diagnostic and other purposes in the fields of, for example, medicine and other industries. An object, such as a patient, may be scanned with a CT system to obtain CT datasets. For reconstruction of computed-tomographic images from X-ray CT datasets, various reconstruction methods have been developed. These methods may roughly be characterized into two classes: analytical methods and iterative type methods.
Analytic method may be applied directly on X-ray CT datasets, sometimes referred to as raw data, to obtain reconstructed images. On the other hand, iterative reconstruction (IR) methods may achieve better resolution for reconstructed image.